Distraction by Salient Stimuli in Adults with Attention-Deficit/Hyperactivity Disorder: Evidence for the Role of Task Difficulty in Bottom-Up and Top-Down Processing

Publication date: Available online 9 February 2018
Source:Cortex
Author(s): Alexander Schneidt, Aiste Jusyte, Karsten Rauss, Michael Schönenberg
The cognitive mechanisms of increased distractibility in attention-deficit/hyperactivity disorder (ADHD) are poorly understood. The current study investigated the influence of two major modulating factors (emotional saliency, task difficulty) on behavioral and electrophysiological parameters underlying distractibility in ADHD. In addition, the attentional focus (indirect and direct processing of distractors) was examined. Thirty-six adults with ADHD and 37 healthy controls completed two experimental tasks while EEG data was collected. Task 1 assessed indirect processing of emotional or neutral distractors during a perceptual judgment task with varying task difficulty. Task 2 measured direct processing of the emotional or neutral stimuli and required participants to rate the stimuli regarding valence and arousal. Adults with ADHD exhibited generally higher behavioral distractibility than healthy controls. Electrophysiological data in the ADHD group indicated an enhanced bottom-up processing (increased early posterior negativity amplitudes) of distractors in trials with high task difficulty as well as enhanced top-down processing (increased late positive potential amplitudes) in trials with low task difficulty. However, no group differences were evident in the neural processing of emotional content or between attentional focus conditions. These findings support the notion that distractibility in ADHD results from impairments to both top-down as well as bottom-up processes and underscore the importance of task difficulty as a modulating factor.



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